First off, what type of bichir?
If it stays in the 10-14 inch range, a 40 breeder would be acceptable
If it gets into the 14-18 inch range, a 75-90 would be acceptable
Anything above that and you are looking at a 125+
Secondly, for temperature high 70s to low 80s,
Third, a relatively neutral pH is good (6.5-7.5), harness doesn't matter too much, just keep it stable.
im getting a Dinosaur Bichir
and when I get it its gonna 3 inches and I got a 20 breeder bare bottom with a hide as a grow out/temporary tank till I can get it a bigger permenant tank that's like 55 60 gal; what foods should I get it? also is itfine if the tank doesn't have a light?
I think bichirs are very cool fish! But I've never tried 1or more because the get so long, 12-18 inches. A friend keeps 2 or 3 in a 6ft tank...tightly covered! I'd guess a 90g is just a starter tank for 1 or 2...& they're predators, so what will you be able to keep with them? That's my issue with them...& I like loaches so much better, lol.
A 20g is not even a short term tank for these fish, a few weeks at most. Don't get even 1 until you have a MUCH bigger tank available. Young fish of large species should grow fast with lots of good foods & lots of water changes. It may take a year or even 3 but that's a minimum!